1. Field of the Invention
This invention relates to a read module including a light source and photoelectric conversion elements for detecting an optical image and a poor connection detection apparatus and a poor connection detection method for detecting poor connection between connectors for connecting the read module and a controller for controlling the read module.
2. Background Art
In related arts, a copy, a facsimile, a scanner, or the like includes a read module for reading an image from an original and the read module includes a light source for applying light to an original and photoelectric conversion elements for converting reflected light from the original in to an image signal. Each of the machines also includes a controller for controlling the operation of the read module, and the read module and the controller have connectors electrically connected to each other by a cable.
By the way, in the configuration of connecting the controller and the read module through the connectors, if poor connection of the connectors occurs, it is feared that it may become impossible to output the normal electric signal to the controller or it may become impossible to normally control the read module, namely, a malfunction may occur. Therefore, the connection of the connector of the read module and the connector of the controller requires high reliability.
Then, for example, in a related art, to detect poor connection between paired connectors for connecting circuit boards, first and second ground terminals are disposed at both ends of a plurality of terminals of the connector and a common ground terminal is disposed at an intermediate point of the plurality of terminals and then the potential difference between the first ground terminal and the common ground terminal and the potential difference between the second ground terminal and the common ground terminal are detected by a potential difference comparison section included in a circuit machine and poor connection is detected based on the difference between the former and latter potential differences. That is, if a pair of connectors made up of a male connector and a female connector is inserted in a mutually inclined state, the potential difference between the first ground terminal and the common ground terminal and the potential difference between the second ground terminal and the common ground terminal differ and therefore the difference between the former and latter potential differences is detected for detecting poor connection between the paired connectors. (For example, refer to JP-A-2001-142797 (p. 3-p. 4, FIGS. 1-4))
For example, in a related art, to detect poor connection between paired connectors in a video camera having a read module such as a camera head and a CPU connected by the connectors, a detection terminal for detecting poor connection between the connectors is further disposed in addition to input/output terminals for controlling the essential operation of the camera head and the CPU, and an electric current flowing through the detection terminal is detected, thereby detecting poor connection. (For example, refer to JP-A-6-339051 (p. 2-p. 3, FIGS. 1-3))
However, according to the detection method of poor connection between the connectors disclosed in JP-A-2001-142797, the connector needs to be provided with the first ground terminal, the second ground terminal, the common ground terminal, and the like in addition to the input/output terminals for inputting/outputting the essential operation signal of the circuit machine. Thus, the number of the terminals of the connector increases and it becomes difficult to miniaturize the connector and the space to which the connector is connected; this is a problem.
Also in the detection method of poor connection between the connectors in the video camera disclosed in JP-A-6-339051, to detect poor connection between the connectors, the detection terminal for detecting poor connection between the connectors needs to be further disposed in addition to the input/output terminals for controlling the essential operation of the camera head and the CPU. Thus, it becomes difficult to miniaturize the connector and the space to install the connector; this is a problem.